Investigation between the relationship of Mass and Time taken while coming down a water slide.

Extracts from this document...

Introduction

Investigation between the relationship of Mass and Time taken while coming down a water slide

In this experiment I am going to investigate the relationship between Mass and Speed of 5 people with different masses coming down a water slide. Firstly, I have obtained evidence by measuring the time taken for people with various different masses to come down a water slide. My prediction is that mass is independent of the time taken. We have used a digital stop watch to measure the time taken of the people coming down the slide. I am going to use several different scientific equations to try and prove my prediction. I also have to take into consideration that the slide is not a straight surface it has several different bumps but I also predict that this has no effect to the time taken as horizontal velocity is independent of vertical velocity because both of these masses are being pulled by gravity at a constant acceleration of 9.8m/s²so all objects free fall at the same rate of acceleration regardless of their mass.

Although we were given the length of the slide I will show how they had calculated by using Pythagoras theorem which says in a right angle triangle the sum of squares of the base and the height is equal to the square of the hypotenuse.

X² = 55² + 50² I cannot be certain if this is the correct

X² = 3025 + 2500 as the slide was not a triangle but I am

X² = 5525 going to carry the error forward to do

X= 74.3 all calculations.

From these results I can rule out the inference, the greater the persons mass the slower a person will go down or faster! This is false because Alan has a greater mass than Omar but his average time was still smaller than Omar’s who has a smaller mass and had a larger time taken.

Back to my prediction which is in a straight that Mass is independent of time taken. To prove this I will use my equation h = ut + ½gt², this is the equation is used whenever an object travels at a uniform acceleration line where h = height, u = initial velocity, v = final velocity, t = time taken and g = acceleration due to gravity which is 9.8 m/s², As you can see mass does not play any role in this equation it is only acceleration that does as it is the acceleration due to gravity.

I am now going to work with the average time taken for the 4 different masses to show you how minor the changes are.

Let’s take Lian who has a mass of 50 kg and whose average time taken was 7.56 and let’s take Alan who has a mass of 64 kg and whose average time taken was 7.63.The difference in mass is 14 kg and the difference in time taken was 0.07 seconds! Even after such a great increase in mass there has hardly been any difference in the time taken.

Let us now take Abhay with a mass of 58 kg and Omar who has a mass of 60 kg which is only a 2 kg change in the mass which is far smaller than the change with Lian and Alan. Abhay’s average time taken was 7.63 and Omar’s average time taken was 7.85, the difference in time taken was 0.22 seconds.

By using these results I can help prove my prediction saying that mass is independent to time taken.

Improvements

To improve the experiment we should have had a straight slide instead of a parabolic surface to be able to calculate the length of slide more accurately using Pythagoras’ theorem.

We could have used light gates instead of stop watches to get exact readings when students start and stop on the slide this way they could avoid any human error.

Each person could have used the same float as they can all encounter the same % of friction.

We could have used different slides to test the effect of friction on different surfaces.

Related GCSE Forces and Motion essays

From looking at my preliminary results, I have come up with my final variables: Maximum height = 260.00cm Minimum height =50.00cm Mass of cup cake = 0.33g (for both cup cakes to make fair test) Prediction My prediction is that the larger the surface area is, the longer the time will be taken for the mass to reach the ground.

0.929 8 4.384 0.831 1.824 0.993 9 4.702 0.831 1.914 1.083 10 5.082 0.831 1.967 1.136 Analysis Conclusion: Our experiment has not proved conclusively that there is a proportional relationship between the factors we are investigating and therefore our hypothesis is not categorically correct We can see, nonetheless that our

stage, it seems sensible to say that a larger mass will result in more kinetic energy, and hence a faster velocity. But lets look at the formula for kinetic energy. Mgh = 1/2mv2 Now we can see here that although a larger mass will indeed result in a larger amount

Our range of masses was chosen to be from 0 - 1 kg with 8 readings on each of the three surfaces. A choice of five surfaces was offered and the three chosen were the ones that differentiated the most from each other.

on making sure that no indentations or dips (changing the angle of the surface), affected the ball's bounce but because we were using a bench surface which had been used many times before to conduct different experiments, there would inevitably be scratches and other such distortions on the surface, which may have affected the bounce back height of the ball.

As soon as the load comes up and is about to go down again, I will then start my stopwatch. I will try to use springs, which all of them have the same length to start off with. And when every experiment has finished, I will put on another spring in series.

To prove this, when we have the results from the practical, I will be able to use a formula and find the relationship between mass and acceleration. I think this will differ from the relationship between the force pulling an object and its acceleration.

The horizontal motion of the projectile is independent of the vertical motion, and that is why the falling motion of the block does not need to be considered. A aluminium block will be used, as it is a fairly dense object.